Moving liner fracturing method

Abstract

A method for treating a production wellbore involves a moving liner run-in on a work string to a treatment zone. Treatment fluid is pumped at high flow rate and pressure down the annulus, through a crossover to the interior of the liner and to the treatment zone. Zones co-extensive with the liner are shielded from treatment as a path of least resistance is defined into the treatment zone. Relatively tight liner clearance and high treatment flow rates prevent treatment of shielded zones. Flow rate is reduced, but pressure maintained, while the moving liner is pulled, exposing another zone.

It is claimed: 
     
         1 . A method of treating a plurality of zones defined along a wellbore extending through a subterranean formation, the wellbore having a cased portion proximate the surface, the method comprising:
 a) making-up and running-in a work string to the wellbore to a position adjacent an exposed treatment zone of the formation, the work string, when made-up, having from top-to-bottom a plurality of tubulars, a perforated sub, an annular seal attached thereto, and a liner;   b) pumping a treatment fluid downhole at a relatively high first flow rate into an annulus defined between the work string and the casing, through the perforated sub, and into an interior passageway defined in the liner;   c) treating the exposed treatment zone, wherein the exposed treatment zone is defined downhole from the lower end of the liner;   d) shielding additional treatment zones with the liner, and preventing effective treatment of the additional treatment zones;   e) pulling the work string uphole and exposing an additional treatment zone while pumping treatment fluid downhole at a relatively low second flow rate; and   f) repeating b) through e), treating the additional exposed treatment zones.   
     
     
         2 . The method of  claim 1 , further comprising: pumping treatment fluid through a surface housing into the wellbore annulus, the housing having a housing seal positioned in an annulus around the work string. 
     
     
         3 . The method of  claim 1 , wherein a) further comprises placing a check valve in the work string above the perforated sub. 
     
     
         4 . The method of  claim 1 , further comprising: sliding the annular seal along the casing. 
     
     
         5 . The method of  claim 1 , wherein a) further comprises: coupling the plurality of tubulars to one another, end-to-end. 
     
     
         6 . The method of  claim 1 , wherein the treatment fluid is fracturing fluid and wherein c) further comprises: fracturing the exposed treatment zone. 
     
     
         7 . The method of  claim 6 , wherein b) further comprises: pumping the fracturing fluid at a relatively high first flow rate of between about 40 and 100 bbl/min. 
     
     
         8 . The method of  claim 7 , wherein b) further comprises: pumping the fracturing fluid at a pressure of around about 4000 psi. 
     
     
         9 . The method of  claim 1 , wherein the liner has a clearance of around about ⅜ inches. 
     
     
         10 . The method of  claim 1 , wherein a path of least resistance is defined for the treatment fluid into the treatment zone in response to a clearance of the liner in the wellbore annulus. 
     
     
         11 . The method of  claim 10 , wherein the path of least resistance is defined for the treatment fluid into the treatment zone in response to the relatively high first flow rate. 
     
     
         12 . The method of  claim 6 , wherein the treatment fluid further comprises: an acidizing fluid. 
     
     
         13 . The method of  claim 6 , wherein b) further comprises: pumping the fracturing fluid at a relatively high first flow rate of above about 40 and 100 bbl/min. 
     
     
         14 . The method of  claim 6 , wherein e) further comprises: pumping the fracturing fluid at a relatively low second flow rate of about 5 bbl/min. 
     
     
         15 . The method of  claim 1 , wherein the exposed first treatment zone is open hole or has a perforated casing or lining. 
     
     
         16 . The method of  claim 1 , wherein pulling the work string in e) further comprises: uncoupling or disconnecting one or more of the plurality of tubulars. 
     
     
         17 . The method of  claim 1 , further comprising: g) treating multiple wellbores extending through the subterranean formation before removing the liner from the well. 
     
     
         18 . A method of sequentially treating treatment zones along a wellbore extending through a subterranean formation, the method comprising:
 a) positioning a liner adjacent to an exposed treatment zone;   b) pumping a treatment fluid downhole into the exposed treatment zone, while shielding additional treatment zones with the liner;   c) moving the liner while pumping treatment fluid downhole, thereby exposing an additional treatment zone; and   d) repeating a) through c), treating additional exposed treatment zones.